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| author | Mikhail Vorozhtsov <mikhail.vorozhtsov@gmail.com> | 2012-07-15 00:53:52 +0700 |
|---|---|---|
| committer | Simon Marlow <marlowsd@gmail.com> | 2012-07-16 11:09:40 +0100 |
| commit | cc456b0be3f20a1c1cef4154ae40ac18f4f6711e (patch) | |
| tree | 0ca2bc0cdfabd6f4c6e3e0a94170baae71d634c0 /docs | |
| parent | b1e97f2f325537664f09eee7ea0e7c53264b061e (diff) | |
| download | haskell-cc456b0be3f20a1c1cef4154ae40ac18f4f6711e.tar.gz | |
Implemented MultiWayIf extension.
Diffstat (limited to 'docs')
| -rw-r--r-- | docs/users_guide/flags.xml | 6 | ||||
| -rw-r--r-- | docs/users_guide/glasgow_exts.xml | 21 |
2 files changed, 27 insertions, 0 deletions
diff --git a/docs/users_guide/flags.xml b/docs/users_guide/flags.xml index 544acd8c2a..24c52f214a 100644 --- a/docs/users_guide/flags.xml +++ b/docs/users_guide/flags.xml @@ -1128,6 +1128,12 @@ <entry><option>-XNoLambdaCase</option></entry> </row> <row> + <entry><option>-XMultiWayIf</option></entry> + <entry>Enable <link linkend="multi-way-if">multi-way if-expressions</link>.</entry> + <entry>dynamic</entry> + <entry><option>-XNoMultiWayIf</option></entry> + </row> + <row> <entry><option>-XSafe</option></entry> <entry>Enable the <link linkend="safe-haskell">Safe Haskell</link> Safe mode.</entry> <entry>dynamic</entry> diff --git a/docs/users_guide/glasgow_exts.xml b/docs/users_guide/glasgow_exts.xml index 805f53aa40..dde235eda4 100644 --- a/docs/users_guide/glasgow_exts.xml +++ b/docs/users_guide/glasgow_exts.xml @@ -1690,6 +1690,27 @@ Note that <literal>\case</literal> starts a layout, so you can write </para> </sect2> +<sect2 id="multi-way-if"> +<title>Multi-way if-expressions</title> +<para> +With <option>-XMultiWayIf</option> flag GHC accepts conditional expressions +with multiple branches: +<programlisting> + if | guard1 -> expr1 + | ... + | guardN -> exprN +</programlisting> +which is roughly equivalent to +<programlisting> + case () of + _ | guard1 -> expr1 + ... + _ | guardN -> exprN +</programlisting> +except that multi-way if-expressions do not alter the layout. +</para> +</sect2> + <sect2 id="disambiguate-fields"> <title>Record field disambiguation</title> <para> |